Wet etching techniques used in the fabrication of integrated circuits on silicon wafers entail exposure of the silicon wafers to one or more etching solutions and one or more cleaning solutions. Such solutions contain particulates that adversely impact the wet etching process, with some of the particulates being formed during the wet etching process itself. U.S. Pat. Nos. 4,899,767, 4,917,123 and 4,778,532 issued to McConnell et al. appear to entail process fluid particulate removal by size-based filters.
For example, hydrogen fluoride-containing acids are used to etch silicon dioxide layers during silicon wafer processing. Fluorosilicate particulates resulting from the etching reaction tend to adhere to the wafers, thereby reducing or destroying the usefulness of a wafer for its intended purpose. Such particulates are difficult to remove by physical (i.e., size-based) filtering techniques. Consequently, methods of removing fluorosilicate and like particulate contaminants from solutions used in the processing of silicon wafers are desired.